(CNSNews.com) – The chairman and the vice chairman of the State Department Accountability Review Board (ARB) that investigated the Sept. 11 terrorist attacks on U.S. facilities in Benghazi, Libya, made dramatically different statements on Wednesday about the duration of those attacks that resulted in the deaths of four Americans.

The relevant duration of the event shrunk from “almost eight hours” to “only about 20 or 30 minutes” when a reporter asked this “accountability” team why the U.S. military had not been sent to Benghazi to help that night.

During his opening statement at a State Department briefing, Ambassador Thomas Pickering, who chaired the ARB, said the terrorist attacks occurred over a span of almost eight hours.

“What happened on September 11th and 12th in Benghazi was a series of attacks in multiple locations by unknown assailants that ebbed and flowed over a period of almost eight hours,” Pickering volunteered.

About 20 minutes later in the same briefing, as Ambassador Pickering nodded his head in agreement, retired Admiral Michael Mullen, the vice chairman of the ARB, put the Benghazi terror event in a very different timeframe. He said it lasted only about 20 or 30 minutes.

Mullen, who formerly served as chairman of the Joint Chiefs of Staff, was responding to a reporter who had asked why the U.S. military never became involved.

“Why such a passing reference to military involvement?” the reporter asked. “Can you explain why they couldn’t have done more?”

“We looked at the force posture very specifically, and while we had a lot of forces in Europe both at sea and on land, it is not reasonable that they could have responded … in any kind of timely way,” said Mullen. “This was over in a matter of about 20 or 30 minutes with respect to the Special Mission specifically. And we had no forces ready or tethered, if you will, focused on that mission so that they could respond, nor would I expect we would have.”

Mullen not only narrowed the length of the terror attack to 20 or 30 minutes, but also defined it as only those events at the “Special Mission” compound, which was the State Department’s facility in Benghazi.

However, a CIA timeline of the Sept. 11 events, which was provided by a senior U.S. intelligence official, and which generally comports with the description of events in the ARB’s own report, shows that about one hour and fifty minutes elapsed between the time the State Department’s “Special Mission” compound first came under attack and the moment when a rescue team from the nearby CIA “Annex” was able to extract the surviving U.S. personnel from that mission.

But even that was not nearly the end of the terror attacks on the Americans in Benghazi that night.

As the State Department security personnel rescued by the team from the Annex fled from the “Special Mission” to the Annex—as both the CIA timeline and the ARB report show—it was attacked. The Annex facility itself was also under fire until about 1:00 a.m.–or about two hours and twenty minutes after the attack first started at the “Special Mission.”

The terrorists would then launch yet another attack on the Annex shortly after 5:00 a.m.

The ARB report itself–which Mullen co-authored–describes the initial attack on the “Special Mission” compound as lasting far more than 20 or 30 minutes. It says that the State Department’s own security personnel and the Annex rescue team left that site without having recovered Amb. Stevens because they were afraid they could no longer hold the location and came under fire even as they were evacuating it.

The following three paragraphs, taken from the ARB’s report, describe first how the State Department’s security team, and then the Annex rescue team, retreated from the “Special Mission” compound even though they had not found Amb. Stevens:

“At the urging of the Annex security team and friendly militia members, who warned that the compound was at risk of being overrun, the TDY RSO [State Department temporary duty regional security officer] and four ARSOs [assistant regional security officers] departed for the Annex without having found Ambassador Stevens. As the Annex team provided cover fire, the five DS agents’ fully armored vehicle departed and took hostile fire as they left the SMC and turned right out of the C1 entrance. The driver, ARSO 1, reversed direction to avoid a crowd farther down the street, then reverted back to the original easterly route towards the crowd after a man whom the DS agents believed to be with February 17 signaled them to do so. Farther ahead, another man in a small group of individuals then motioned to them to enter a neighboring compound, some 300 meters to the east of the C1 entrance of the Special Mission compound. The DS [State Department Bureau of Diplomatic Security] agents suspected a trap, ignored this signal, and continued past. The group along the route then opened fire at the vehicle’s side, shattering and almost penetrating the armored glass and blowing out two tires. While the identities of the individuals who fired upon the DS agents is unknown, they may have been part of the initial wave of attackers who swarmed the SMC earlier that night. A roadblock was present outside this compound and groups of attackers were seen entering it at about the time this vehicle movement was taking place.”